title: Incidence of symptomatic A(H1N1)pdm09 influenza during the pandemic and post-pandemic periods in a rural Indian community.
abstract: BACKGROUND
  Data on influenza illness rates with population denominators are needed to quantify overall morbidity and to prioritize public health intervention strategies.
  
  
  METHODS
  The rates of influenza A(H1N1)pdm09 infection during pandemic phases were determined in a longitudinal community cohort study as part of an influenza vaccine study in a rural community of North India.
  
  
  RESULTS
  During the 711,731 person-weeks of surveillance, a total of 1410/7571 (19%) febrile acute respiratory illness cases were positive for influenza. Of these, 749 (53%) were influenza A(H1N1)pdm09, 643 (46%) influenza B, and 18 (1%) influenza A (H3N2). The overall incidence rate of influenza-associated febrile acute respiratory illness was 128/1000 person-years. The incidence rates of influenza A(H1N1)pdm09 were high during both the pandemic phase (179/1000 person-years; November 2009 to January 2010) and post-pandemic phase (156/1000 person-years; August to October 2010), with children<18 years of age being at the greatest risk of influenza infection in the community.
  
  
  CONCLUSIONS
  These findings provide important information for planning clinical and public health intervention strategies to mitigate the impact of influenza epidemics.
authors.affiliation: Department of Pediatrics, 1600 7(th) Ave So CHB 304, University of Alabama at Birmingham, Birmingham, AL 35233-0011, USA. Electronic address: kfowler@uab.edu.
authors.forename: Karen B
authors.initials: KB
authors.lastname: Fowler
authors.forename: Vivek
authors.initials: V
authors.lastname: Gupta
authors.forename: Wayne
authors.initials: W
authors.lastname: Sullender
authors.forename: Shobha
authors.initials: S
authors.lastname: Broor
authors.forename: Marc-Alain
authors.initials: MA
authors.lastname: Widdowson
authors.forename: Renu B
authors.initials: RB
authors.lastname: Lal
authors.forename: Anand
authors.initials: A
authors.lastname: Krishnan
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007251:Influenza, Human / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012424:Rural Population; D055815:Young Adult
keywords: Cohort; Epidemiology; Incidence; Influenza A(H1N1)pdm09; Rural India